This invention relates to a method for controlling positions of reproduction pictures on a recording film mounted to a recording cylinder in the direction of the cylinder's axis, for use in a picture reproducing machine, such as a color scanner, or a color facsimile.
A picture reproducing machine such as a color scanner, wherein a plurality of original pictures mounted to a picture cylinder are scanned by a pickup head to obtain picture signals, wherein reproduction pictures with variable reproduction scales are recorded exactly by a recording head on a recording film mounted to a recording cylinder in the desired layout positions by using the picture signals according to the desired trimming of the pictures, has not been developed yet. One of the reasons is a fact that the positions of the reproduction pictures on the recording film in the direction of the recording cylinder's axis cannot be precisely controlled.
For example, in a conventional picture scanning and recording machine the moving speed of the recording head in the direction of the recording cylinder's axis is fixed, but, while the picture are scanned photoelectrically, the moving speed of the pickup head in the same direction is varied depending on the reproduction scale, thereby changing the reproduction scale of the reproduction picture in the direction of the recording cylinder's axis.
However, in this embodiment, the response time to the voltage supplied to a motor for driving the pickup head is not stable, i.e. the time the motor comes up to a speed corresponding to the voltage supplied after changing the supply voltage depends on the voltage before the supply, the difference between the voltages before and after the supply, and so forth, and thus the starting point of the reproduction picture in the direction of the recording cylinder's axis is shifted several by scanning lines.